Abstract 17874: Decline in the Ankle Brachial Index and Functional Outcome in Patients with Peripheral Arterial Disease
Background: Patients with lower-extremity peripheral arterial disease (PAD) have greater functional impairment and faster functional decline compared with individuals without PAD. Furthermore, a decline in functional performance is associated with an increased risk for later mobility loss. Whether greater declines in the ankle-brachial index (ABI) predict higher annual decline in office-based functional performance measures or mortality in PAD is unknown. We hypothesized that patients with PAD with greater declines in ABI over a 2-year period would have higher annual decline in six-minute walk in the subsequent period.
Methods: Participants were part of the WALCS (Walking and Leg Circulation Study) and WALCS II prospective, observational studies designed to identify clinical characteristics associated with functional decline and mortality in PAD, defined as an ABI 0.15 at any point in the first two years of follow up. The associations of ABI decline with the functional decline at subsequent follow up were explored using a mixed model adjusted for age, sex, baseline ABI, prior year functional performance, race, BMI, smoking, baseline comorbidities, and study cohort. In a secondary analysis participants with ABI < 0.40 were excluded because of their risk of critical limb ischemia.
Results: A total of 348 and 319 participants with PAD were included in the primary and in the secondary analyses, respectively. The mean follow up was 43.0 ± 25.9 months. The associations between the change in ABI and the annual decline in six-minute walk are reported in the table.
Conclusion: In participants with PAD, a decline of ABI of > 0.15 at any point over a 2 year period is associated with subsequent worse decline in 6 minute walk compared with a decline of ABI of ≤ 0.15 or with no decline.
- © 2012 by American Heart Association, Inc.